PAD CONDITIONER DRESSER
Methods for extending the service life of a CMP pad dresser having a substrate and a plurality of superabrasive particles disposed thereon which is used to dress a CMP pad are disclosed and described. The method may include dressing the chemical mechanical polishing pad with the dresser; determining superabrasive particle wear by measuring a mechanical property of the pad, dresser, or combination thereof; and responding to the mechanical property measurement by varying pressure and RPM between the pad and the dresser in relation to the superabrasive particle wear in order to extend dresser life. Additionally, a method may include dressing the chemical mechanical polishing pad with the dresser; vibrating, in a direction substantially parallel to a working surface of the pad, a member selected from the pad, the dresser, a wafer being polished by the pad, or any combination thereof, to minimize a mechanical stress on the pad, dresser, wafer, or combination thereof.
1 . A method for extending the service life of a chemical mechanical polishing pad dresser used to dress a chemical mechanical polishing pad, the dresser having a substrate and a plurality of superabrasive particles disposed thereon, comprising:
dressing the chemical mechanical polishing pad with the dresser;
determining superabrasive particle wear by measuring a mechanical property of the pad, dresser, or combination thereof; and
responding to the mechanical property measurement by varying pressure and RPM between the pad and the dresser in relation to the superabrasive particle wear in order to extend dresser life.
2 . The method of claim 1 , wherein the measured mechanical property is selected from the group consisting of frictional force, acoustic emission, temperature, pad reflectivity, pad flexibility, pad elasticity, and combinations thereof.
3 . The method of claim 1 , wherein varying the pressure and RPM includes gradually increasing the pressure and RPM between the pad and the dresser.
4 . The method of claim 3 , wherein the gradual increase for the pressure and/or RPM over time is a nonlinear exponential increase.
5 . The method of claim 1 , wherein varying the pressure and RPM includes automatically increasing the pressure in response to increased superabrasive particle wear.
6 . The method of claim 1 , further comprising vibrating, in a direction substantially parallel to a working surface of the pad, a member selected from the pad, the dresser, a wafer being polished by the pad, or any combination thereof, to minimize a mechanical stress on the pad, dresser, wafer, or combination thereof.
7 . The method of claim 6 , wherein the dresser vibrates in a lateral, circular, elliptical, or random motion substantially parallel to the working surface of the pad.
8 . The method of claim 6 , wherein the vibrating is only in a direction parallel to a working surface of the pad.
9 . The method of claim 6 , wherein the vibrating is at an ultrasonic frequency greater than 15 kHz.
10 . The method of claim 6 , wherein the vibrating is continuous.
11 . The method of claim 6 , wherein the vibrating is diffused.
12 . The method of claim 1 , wherein pressure and RPM is increased when the chemical mechanical polishing pad surface exhibits a decrease in average asperity density, average asperity depth, average asperity width, average asperity length, or combination thereof.
13 . A method for extending the service life of a chemical mechanical polishing pad dresser used to dress a chemical mechanical polishing pad, the dresser having a substrate and a plurality of superabrasive particles disposed thereon, comprising:
dressing the chemical mechanical polishing pad with the dresser;
vibrating, in a direction substantially parallel to a working surface of the pad, a member selected from the pad, the dresser, a wafer being polished, by the pad, or any combination thereof, to minimize a mechanical stress on the pad, dresser, wafer, or combination thereof; and
varying the pressure and RPM between the pad and the dresser, including gradually increasing the pressure and/or the RPM between the pad and the dresser in a non-linear manner over time as the dresser is used, such that the dresser life is extended, wherein the pressure and the RPM is increased when the chemical mechanical polishing pad surface exhibits wear.
14 . The method of claim 13 , further comprising determining superabrasive particle wear.
15 . The method of claim 14 , wherein determining superabrasive particle wear includes measuring a mechanical property of the pad, dresser, or combination thereof.
16 . The method of claim 15 , wherein the measured mechanical property is selected from the group consisting of factional force, acoustic emission, temperature, pad reflectivity, pad flexibility, pad elasticity, and combinations thereof.
17 . The method of claim 16 , wherein determining superabrasive particle wear further includes examination of a dressed chemical mechanical polishing pad surface.
18 . The method of claim 17 , wherein pressure and RPM is increased when the chemical mechanical polishing pad surface exhibits a decrease in average asperity density, average asperity depth, average asperity width, average asperity length, or combination thereof.
19 . The method of claim 14 , wherein determining superabrasive particle wear further includes an estimation of superabrasive particle wear based on dresser use.
20 . The method of claim 13 , wherein the vibrating is only in a direction parallel to a working surface of the pad at an ultrasonic frequency greater than 15 kHz.